Tamil Nadu ranks third in the installed solar capacity in India as of September 2024. It has 8,462.92 MW of ground-mounted solar; however, only a fraction–792.17 MW–is rooftop solar.

Experts told Mongabay India that despite its abundant potential in sunny states like Tamil Nadu, the uptake of rooftop solar has been very slow. This year, the central government launched the Prime Minister’s Surya Ghar scheme, which offers subsidies for installing rooftop solar of up to 3KW. As part of this, Tamil Nadu’s state-owned electricity production and distribution company (until recently, called Tamil Nadu Generation and Distribution Corporation Limited, or TANGEDCO) announced that it will set up rooftop solar panels in 25 lakh homes in the next few years.

This goal might be too ambitious, say experts. Rooftop solar is currently installed only in a little over 13,000 homes; even after this scheme’s launch, the uptake has been slow.

This is because rooftop solar reduces consumers’ dependence on TANGEDCO and introduces complexities in how TANGEDCO manages the grid and collects revenues. Therefore, state utilities, which have huge investments in infrastructure and human resources to operate the energy grid, play a paradoxical role in promoting rooftop solar. They stand to lose the very customers that run their operations.

“The model on which the utility survives—selling power, getting revenue– is under question. The old world thinking is to figure (out) that you go slow on your target until you can figure a way out for yourself,” explains K Vishnu Mohan Rao, Senior Researcher, Electricity Governance, Citizen Consumer and Civic Action Group (CAG). Some ways to deter prosumers (consumers who also produce electricity) have been to use revenue levers like network charges–a small fee paid by prosumers for using the grid–and by offering lower prices for power sent to the grid and charging commercial prosumers a higher price when they consume from the grid. Return on investment is a big question for prosumers who spend a few lakh rupees to install solar rooftops, even with the subsidy. These tariffs and policies delay the returns, according to some experts and prosumers.

In this video, we investigate the factors that have hindered the uptake of rooftop solar and will continue to be a barrier to the success of the PM Surya Ghar scheme.

Watch: [Video] Why rooftop solar is struggling in Bengaluru

This content was produced and developed with the Internews’ Earth Journalism Network.